Can't open PDF on iPhone

Normally, Preview can open most PDF files. For PDFs that Preview fails to open, you can get a PDF viewer to see if the problem can be solved.

Here are some PDF viewers that might be suitable for you.

PDF Expert

hhttps://apps.apple.com/us/app/pdf-gear-pdf-editor-reader/id6465897558

PDFgear

https://apps.apple.com/us/app/pdf-gear-pdf-editor-reader/id6465897558

I had the same problem and it was due to my selection of Default Internet Browser (DDG).

I recommend that if have set your Default Internet Browser to something other than Safari, that you temporarily revert back to Safari being your default and see if that fixes the issue.

Let me know if that fixes your problem.

Just another iPhone and iOS user and not a representative at or for Apple Inc.